I think my water neck was leaking a bit. Took it off and the o-ring is a bit rough looking. I have one of these aluminum rubber gaskets. Can I just pull out that o-ring and replace it with that gasket or is the seal compromised due to the neck's o-ring design? Thanks!
Should be able to,, Check straightness of the thermostat housing with a file to make sure it's close to being flat no more the Like .005 You just snug tight bolts like 15ish ft pds
SBC? O-ring is not OE style, is the neck designed for one? If you can't find a replacement o-ring for your neck, the one shown should still provide a seal. The sealing surface is a full 360 circle that is roughly 3/8" diameter. A small gap around this should still allow a seal inside and outside this groove for the o-ring. Hot rodders are always mixing and matching parts, but you gotta take into account what the differences are and how they stack up. Just look at where everything aligns. You can use a sealer to 'fill' that o-ring groove, too. Is your intake surface also different?
If it's one of the cheesy chrome thermostat housings, throw it away. I had one, filed it flat a few times, but the metal was so soft (I say metal, but mean whatever it was made of), merely snugging the bolts back up against the rubber o-ring was enough to introduce more warping.
@anothercarguy Cheap chrome the reason is it bows Because cheap & O ring in center so when you tighten it bows ,, Better choice What Op shown , or use full gasket If you have a option get a Oem or Good Quality
Thanks for the help! It is a chrome neck. I too have read that they are cheap and prone to fail. Sounds like I should get an OEM one. I have an aluminum intake as well.
Your Intake more likely good quality aluminum versus thermostat housing. Not all Chrome have issues But if it like $ 15 new its cheap one. Yes the do Decay / rot .. Leaking when New is because it bows when tightening or over tightening & the O rig it bows Cheap non Billet ones
The only thing those cheap chrome jobs are good for is keeping a bit of coolant in while you look for a cast iron housing.
Just did some digging and found this https://www.jalopyjournal.com/forum/threads/straight-sbc-thermostat-housing.1204045/#post-15816964
There are two types of thermostat housings I know of, one is die-cast and the other is aluminum. I have replaced two of the die-cast because they developed pin holes because of galvanic action. I now have the aluminum on both my cars and haven't had an issue since. I also had issues with the gasket you picture and took the thermostat housing off my car, cleaned it up and reinstalled it and had a leak a month later. I now use a stock type gasket and have had zero leaks on over a year.
GM sold gaskets with silicone raised face seal similar to oring at one time . All I would use in my GM tinkering days
O-ring + standard "paper"/Fel-pro gasket or O-ring only mated to manifold? Maybe less is more in this situation?
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